JPS60122036A - Reactor packed with catalyst - Google Patents

Abstract

PURPOSE:To increase flow velocity of gas and heat transfer coefft. and to prevent thermal deterioration of catalyst and increase of impurities by arranging a catalyst layers and layers of heat exchanging pipe nest adjacent and alternately to each other. CONSTITUTION:Coolant is introduced from a coolant feeding port 12, and sent to a coolant distributing header 9 through a coolant falling pipe 7 and plural coolant conduit 8, where the coolant is distributed to a heat exchanger pipe 2 until it reaches an upper coolant collecting header 10 while performing heat recovery. Further, the coolant is transported to a vapor-liquid drum 11 of the coolant through a coolant conduit 8 and taken out of an exhaust port 13. The catalyst is charged from a catalyst charging port 16 at the top of a pressure resistant external shell 1 to feed to spaces between layers of heat exchanging pipe nest adjacent to each other. Packing of the catalyst is thus possible. Reactant gas is introduced from a reactant gas feeding port 14 to a space 5 in the pressure resistant external shell 1, and the gas after completion of reaction is discharged from an exhaust port 15 of the reactant gas.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in reactors for reacting fluids in the presence of catalysts. More specifically, when a catalytic reaction involving exotherm or endotherm is achieved to a desired reaction rate under a predetermined pressure and temperature, the reaction heat generated is recovered or the necessary reaction heat is supplied. However, the present invention relates to an improvement in the reactor structure that can bring the temperature distribution of the catalyst layer closer to the optimum distribution required for the process.

The structural shortcomings of conventional reactors will be explained below using methanol synthesis from synthesis gas as an example.

Methanol synthesis using synthesis gas whose main components are carbon monoxide and hydrogen uses a copper-based catalyst to produce methanol at a pressure of 50 to 3
00 kg/m'G and a temperature in the range of 200 to 600°C are generally used, but if the reaction heat generated at this time is not removed during the reaction process, the reaction gas and catalyst layer will be separated. This causes an excessive rise in temperature, which in turn leads to deterioration of the catalyst, an increase in the production of impurities, and a decrease in the concentration of the desired product from the viewpoint of chemical reaction equilibrium. To prevent this, various methods and structures have been devised to remove the reaction heat and prevent the reaction temperature from becoming too high.

In recent years, as a method for processing the reaction heat, there is a method of cooling the reaction gas and catalyst in the catalyst layer by indirectly transferring the reaction heat to a heat medium. As a heat medium in this case (
・Evaporable water, evaporative water, etc. having an appropriate boiling point, latent heat of vaporization, specific heat, etc. are used, and the heat of reaction is recovered in the form of sensible heat or latent heat of vaporization of these liquids. What is desirable for practical use is to use water as a heat medium, set the temperature lower than the reaction temperature to the boiling point, and boil the water at a corresponding saturation pressure to generate high-pressure steam. The reaction heat is recovered in the form of vaporized heat, and the disadvantages of three typical conventional reactors used for this purpose are described below.

The first example is proposed in Japanese Patent Publication No. 58-39572, and in FIG. 1, tr of the reactor shows a horizontal cross section of the central part. This method consists of a catalyst layer 19 in the reactor in FIG.
By arranging ring-shaped refrigerant headers above and below the catalyst layer, and connecting both ends of the heat exchange tube 2 that vertically penetrates the catalyst layer to the header, the tube plate is eliminated and the cylindrical outer By providing catalyst-free spaces 5 and 6 at the outer periphery and center of the shell 1 and allowing the reaction gas to flow radially from one of these spaces to the other, the gas flow cross-sectional area is increased and pressure drop is reduced. This is what is being measured. At this time,
The catalyst layer 19 is housed between partition walls formed by overlapping the porous plate catalyst receiver 6 and the mesh 4 on the inner and outer circumferential sides, respectively. It is still a tube consisting of a pressure-resistant outer shell 1 and a large number of heat exchange tubes!
In order to absorb the difference in thermal expansion of is supported at the bottom of the pressure-resistant outer shell, and the heat exchange tubes are buried within the packed bed.

Next, the second example is proposed in Japanese Patent Application Laid-Open No. 58-112044, which has almost the same configuration as the first example, and has a large number of heat exchange tubes, one by one, vertically extending the catalyst layer. The reactant gas is flowing in a radial direction perpendicular to the refrigerant flow in the heat exchange tubes. 1. Main difference between the first and second examples
First, the heat exchange tube group including its header is fixed to the upper lid part of the cylindrical pressure-resistant outer shell 1, and the first layer of the catalyst particles etc. layer has the lower part covered with blood as in the first example. It is supported at the bottom of the pressure shell.

The fifth example is the one proposed in Japanese Patent Application Laid-Open No. 58-112046, and is a horizontal section 1r11 at approximately the center of the reactor.
is shown in No. 21 ¥1. In FIG. 2, the example of elephant 75 is
The fundamental difference from the previous two sides is that (C'1) the reaction gas is introduced into the reaction gas supply space 5 in the external use 1, and the catalyst + < 5
It is designed to flow in the string direction inside H19, collect the gas after reaction in the reaction gas gathering space B, and take it out to the outside with a latch.In other words, it is characteristic that the reaction gas flows in the string direction. be. In addition, in Fig. 2, 2 is a heat exchanger pipe, 4 is a mesh, and 7 is a cold-boiled downcomer pipe.

The following two points are common to the six conventional examples described above. That is, (1) each heat exchange tube penetrates through the catalyst layer, in other words, the space outside the heat exchange tubes is filled with catalyst particles, and (2) each heat exchange tube is directly supported at the bottom of the pressure-resistant shell. The heat exchange tube group is configured to be buried in the catalyst particle layer, that is, the lower part of the melting medium particle layer is supported by the outer shell.

In the following, it will be explained that the above two points cause shortcomings of the conventional reactor.

The first drawback is that the tube gaps in the heat exchanger tube bank become too large in order to achieve sufficient heat transfer area to recover the highest possible level of steam from the reactor without thermally degrading the catalyst. Because of the small size, it becomes difficult to fill the gap with the catalyst and discharge the catalyst from the gap. Increasing the gap by increasing the tube arrangement pitch or decreasing the tube diameter;
Alternatively, by reducing the catalyst particle size, filling and discharging the catalyst becomes easier, but since the heat transfer area per unit volume of the catalyst is insufficient, the reaction temperature becomes high especially near the inlet of the catalyst bed where the reaction rate is high. Problems such as accelerated catalyst deterioration and increased impurity generation occur. To simply lower the reaction temperature, the temperature of a refrigerant such as boiling water may be lowered, but high levels of steam cannot be recovered. Therefore, in order to secure the necessary heat transfer area, the pipe diameter and arrangement pitch were reduced.
If heat transfer fines are installed in step 4, the medium filling rate will be low and the discharge will be difficult, resulting in 111f, so it is necessary to reduce the catalyst particle diameter. However, in case 1-, taking methanol synthesis as an example, the catalyst effectiveness coefficient, pressure drop, manufacturability, etc. should be considered. , j7, the equivalent diameter is usually 5 to 6 mm
Spherical, cylindrical and columnar particles of φ are used, and if the diameter is made smaller than this, the following J:Uma yq will occur 1, -1, that is, 1jα Increase in manufacturing cost and increase in pressure loss In addition to the increase in circulating gas compression power costs,
-jθ tends to close, especially in the lower part of the contact layer, and Keo fluid density tends to occur, and as a result, the reaction gas bias f/if in 12
There is also a good chance that this will happen.

Furthermore, using the case of methanol synthesis as an example, it will be explained using FIGS. 6 and 4 that it is difficult to secure the required heat transfer area per unit catalyst volume in a conventional reactor.

Figure 3 shows that 1011 kg/calendar of reaction gas is introduced into a conventional reactor at 240°C, and boiling water (250°C) is introduced into the heat exchange tube.
H2 and CO while cooling the catalyst layer by flowing 40 kg/J of steam recovery).

2 shows the relationship between the average reaction gas temperature in the catalyst layer and the methanol concentration distribution in a conventional reactor when methanol is synthesized from synthesis gas containing CO as a main component. OA in the figure is the overall heat transfer coefficient U (Kca7/m2h・℃)
and the heat transfer surface per unit volume of catalyst fat A (m27
m” of Cata, ), and in Fig. 3, UA=80. [] 00 (, KcaA/h't>m
3ofOata, ). As can be seen from Figure 3, the maximum temperature of the reaction gas in the catalyst layer (this can be considered the temperature of the catalyst) is approximately 280C, which is the temperature limit of normal copper catalysts, which is 260 to 620C. , the average temperature is 280°C or less. Conversely, if the maximum temperature of the catalyst layer is 28
To keep the temperature below 0℃, UA must be at least 80.000
(:KaaA/h-℃am”of 0ata, )
It turns out to be necessary.

Figure 4 shows that in methanol synthesis, boiling water is passed through a heat exchanger penetrating the catalyst layer of a conventional reactor, and the boiling S
What kind of gas is used when the reaction heat generated in the catalyst layer is transferred to the boiling water by flowing the reaction gas in a direction perpendicular to the direction in which the water flows?
An example of the relationship between the overall heat transfer coefficient and the F column speed is shown. In general, in the method of flowing the reactant gas in the radial direction or the chord direction, as seen in the conventional apparatus described above, the ;rA 31 of the gas
=4 Since the area becomes a dog, the superficial velocity decreases and the pressure drop decreases, which is an advantage (C), but on the other hand, as shown in FIG. 4, there is a disadvantage that the heat transfer coefficient becomes small.

The overall heat transfer coefficient was slightly increased to 800 (KcaA,/m
2h・℃), the required heat transfer area A-so,ooo-
=: 00 100 (m”/m3of (!ata').By the way, if the heat exchange tube has an outer diameter of 254 mm and a 1E pitch of 55 mm, then 1 ((μmd = 51〒 The minimum gap between the walls is 29.6 mm.
FA is the minimum distance that catalyst particles with a diameter of 17a - 6n and φ can be packed without forming a bridge (150 g, several times the particle diameter)
m is equivalent to f- [Since it is possible to fill and discharge catalyst particles with a diameter of 6 mm, the heat transfer surface per unit volume of the catalyst is approximately 50 m3, so as mentioned above, 40 kg/- In order to recover the steam and keep the catalyst layer temperature below 280°C, which is necessary to prevent catalyst thermal deterioration and increase in waste materials, it will be impossible to secure the heat transfer area of 100 m2tJ, which is essential.

Therefore, in conventional equipment, it is either possible to get away with low-pressure steam recovery, raise the catalyst layer temperature/accept some degree of catalyst deterioration and increase in impurity formation outside the layer, or if these are not allowed. Instead of securing the heat transfer area, either accept the above-mentioned problems related to the particle size, or fill the upstream of the reactor (fllf with a catalyst with a slightly lower activity). It seems necessary to take countermeasures against temperature peaks by installing additional reactors.

The second drawback is that the lower part of the catalyst particle layer is supported by the bottom of the pressure-resistant shell, and the particles J? Because the heat exchange tube group is buried inside the outer shell, there is a difference in the mechanical contact between the tube group and the particle layer when the tube group thermally expands. Problems such as buckling may occur due to excessive stress acting on the tube group.This phenomenon can be avoided if the pressure-resistant outer shell and the grains of the heat exchange tubes are used as a counterbalance. Although we are moving towards solving the problem of reducing the difference in elongation, we are using materials for the heat exchange tubes that are more inert against impurity formation, and improving the abrasiveness of the pressure-resistant outer shell.
If the coefficient of thermal expansion is different from that of the material, the above-mentioned problem becomes more obvious.

The present invention was made to eliminate the drawbacks of the conventional device as described above, and its purpose is to
”: It is not necessary to make the catalyst particle size smaller than that of ordinary commercially available products, but the charging and discharging of the catalyst is at your discretion, and by maintaining the heat transfer area as desired, the temperature of the catalyst layer can be adjusted. It is easy to set the temperature in the 6-λ degree range where deterioration and impurity formation are not a problem, and the reaction heat can be recovered as high-level thermal energy (high-pressure steam, etc.). An object of the present invention is to provide a catalyst-filled reactor that can alleviate various problems caused by mechanical interaction between a layer of particles such as a catalyst and a layer of particles such as a catalyst.

The advantages of the present invention are as follows: (1) A reaction in which the reaction gas is caused to flow approximately in the radial direction or approximately in the chordal direction of the reactor while cooling or heating the catalyst layer using heat exchange tubes installed approximately vertically. In the vessel,
A catalyst-filled reactor characterized in that catalyst layers and layers of heat exchange tube groups are arranged adjacently and alternately.

(2) The reaction gas is transferred to the reactor while cooling or heating the catalyst layer using a heat exchange tube installed almost vertically.
In a reactor configured to flow in a radial or approximately chordal direction, catalyst layers and layers of heat exchange tube groups are arranged adjacently and alternately, and a structure including the heat exchange tube group is fixed to the upper part of the outer shell. . A catalyst-filled reactor, characterized in that the heat exchange tube group and the catalyst layer are suspended above the outer shell, and the catalyst receiver is housed in a basket.

It is in a place where we provide.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the details of the present invention will be specifically explained with reference to the drawings, based on an embodiment of the catalyst-filled reactor according to the present invention, and taking as an example the case where it is applied to methanol synthesis from synthesis gas.

Figures 5 and 6 are explanatory diagrams of an example of a &! medium charging reactor according to the present invention, and Figures 7 and 8 i+:t: the present invention. ni”:ru1doku・i1ju”τ”・
1 Reactor Q) Another V) Actual 11! FIG. 1 is a diagram illustrating an example of the i aspect.

To book 9, the back r modification of Ming's reactor is deceived by the following point,
2'l, -J-/1: Wow, first feature U1:,
The catalyst layer and the heat exchange tubes 4jY) C′i are arranged in several layers alternately in Table 1, with the phase p° 4(, L, , M7 medium flow l
By flowing the reaction gas in a direction perpendicular to I, 3.a) 3. Jin's 7 heat exchange tube group j intragastric gap ir < 7 Jrp contact hood 4
:full'ji-J-ru must be no υ, /bar(g, catalyst layer e, relatively wide gap ('(=・lfi usual nT-ffi shisa・
fzuru ((ha1゜o standing child zo IL4
te ino 1 le ° 4zu JL, lr well, said office 1 (medium IX'
8, +iyr thermal V(- reaction [and the temperature is raised to lr gas'(
[-heat exchanger run') = layer i'il of group i; 47(t
l) 人IIzuJ'lI]: 艮い、とのと～、'しゅうみふわすい（(、' (t, ):、Igli!
'J J-, since there is no l'J array pitch y, i enough d
-6〈と汀/) pukoya), the gas 4if speed increases, and the low μ1 relationship a) fire value decreases 4)-・20th of the reactor of the present invention The structure of the tube 71゛C is firmly attached to the upper part of the pressure-resistant outer shell, supported in a vertical shape, and the catalyst particle layer is housed in a basket supported at the upper part of the pressure-resistant outer shell. Even if the body and the basket are made of the same material (for example, austenitic stainless steel) and the pressure-resistant outer shell is made of a different material (such as low-alloy steel), the thermal expansion of the tube group structure This is because the problem of mechanical interaction between the tube group structure and the catalyst particle layer can be reduced.

The first embodiment will be explained and explained with reference to FIG. In Fig. 5, 1 is a cylindrical pressure-resistant outer shell that is firmly mounted, and inside it is a basket supported at the upper part of the pressure-resistant outer shell (this is separated from the top in the figure by a perforated plate 21). Catalyst receiver 6
, a catalyst layer (constructed by integrating a medium-receiving bottom plate 22), and inside the basket, a tube group layer consisting of a large number of heat exchange tubes 2 and a catalyst layer 19 are alternately arranged next to each other. At the same time, each replacement of the heat exchange tube group is fixed to the upper part of the pressure-resistant outer shell 1.

In the above configuration, the behavior of the refrigerant will be explained first. In methanol synthesis, boiling water under pressure is optimal as a refrigerant, and this type of refrigerant is introduced from the refrigerant supply port 12 and sent to the refrigerant distribution header 9 via the refrigerant downcomer pipe 7 and a plurality of refrigerant conduits 8. Here, the refrigerant is distributed to each heat exchange tube 2 and is recovered while reaching the upper refrigerant collecting header 1o.Then, the refrigerant is further passed through the refrigerant conduit 8 and reaches the refrigerant gas-liquid drum 11 at -, where it is discharged. Take it out from exit 13.

Therefore, the catalyst is introduced from the catalyst filling port 16 at the top of the surface pressure outer shell 1, and placed in the space between the layer of the arm tube group and the However, inert i and d particles are placed at the bottom and top of the layer 19, respectively, in order to prevent the uneven flow of the reaction gas. It may also be filled with particles.

In order to take out the deteriorated catalyst from the reactor after a long period of use, the pressure-resistant outer shell 1 and the two catalyst take-out ports 17 at the bottom of each of the catalyst receiver baskets may be sequentially opened.

Furthermore, after the reaction gas is introduced into the reaction gas supply space 5 on the left side of the figure of the pressure-resistant outer shell 1 via the reaction gas supply port 14, the reaction gas is introduced horizontally, that is, in the approximately cylindrical outer shell, in the chord direction. While flowing, the cooling operation in the heat exchange layer of the reactor in the catalyst layer is repeated alternately to reach the reaction gas gathering space B on the right side of the figure of the pressure-resistant shell 1, and the gas after the reaction is completed. The reaction gas is taken out from the outlet 15. FIG. 6 shows the AA cross section in FIG. 5, and as mentioned above, the catalyst layer 1
9 and a large number of layers of heat exchange tubes 2 are arranged alternately so that the flow direction of the refrigerant in the heat exchange tubes and the flow direction of the reaction gas (arrows in the figure) are perpendicular to each other.

FIG. 7 is an explanatory diagram showing another embodiment of the catalyst-filled reactor according to the present invention, and FIG. 8 is a diagram showing a cross section taken along line AA in FIG. 7.

The flashing symbols in the figures have the same meanings as in FIGS. 5 and 6.

In the second example shown in FIG. 7.8, the catalyst layer 19 and the layers of the tube group consisting of a large number of heat exchange tubes 2 are arranged concentrically and alternately. A reaction gas supply space 5 and a reaction gas gathering space 6 are provided in the center, and the reaction gas introduced from the reaction gas supply port 14 first fills the reaction gas supply space 5, and then flows through the catalyst layer and the heat exchange tube group. While repeating reaction and cooling operations by alternately circulating the layers in a radial direction, the reaction gas is collected in the reaction gas collection space B, and then taken out from the reaction gas outlet 15. The difference between the second example and the first example shown in FIGS. 5 and 6 is that
The flow direction of the reaction gas is radial, and therefore the catalyst layer and the heat exchange tube group 1- are arranged concentrically. In Figures 7 and 8, the reaction gas is
Although it is supposed to flow radially from the inside toward the shear from 1411, it is also possible to flow from the inside to the outside 1411 if desired.

In addition, in the above two embodiments as well, one of the heat exchange tube groups
- In order to prevent catalyst particles from entering, both sides of the tube group layer may be covered with a net or perforated plate, or the gaps between the tubes may be bridged and the particles may be difficult to pass through. (Several times or less the particle diameter, preferably 2 to 3 times or less).

What can be said from the above-mentioned operation of the reactor of the present invention is that, as mentioned above, the first feature is that it is easy to charge and discharge the catalyst, and that the desired heat can be obtained regardless of the catalyst filling and discharge. The heat transfer area of the exchange tubes can be secured, and as a result, the reaction heat can be recovered in the form of high-level thermal energy (high-pressure steam, etc.), and the combination of the appropriate catalyst layer thickness and the layer thickness of the heat exchange tube group Since it is important to maintain the catalyst layer temperature below the catalyst copper thermal temperature, it is possible to prevent catalyst deterioration and increase in impurity generation as the temperature rises. As mentioned above, by fixing both the catalyst receiver basket and the structure of the heat exchange tube group at the upper part of the outer shell and making the materials of both the same, it is possible to prevent the catalyst from expanding due to the thermal expansion of the tube group. Possibilities such as damage to the equal particle layer, compaction, tube seat hn, etc. are completely avoided, and it is possible to use an inexpensive material different from that of the tube group as the material for the blood pressure outer shell.

As described above, the reactors ff and j2 of the present invention solve the drawbacks of the conventional device U, and in particular, in methanol synthesis from synthesis gas that generates heat, the reaction heat can be converted into high-quality thermal energy (high-pressure Since the catalyst layer can be cooled while recovering steam (steam, etc.), thermal deterioration of the catalyst and increase in impurity generation due to overheating can be stopped by 1'rjj (in addition, the catalyst loading reaction, which facilitates catalyst loading, can be It is a vessel.

[Brief explanation of drawings]

11 (and Figure 2 shows the water and
FIG. 3 is a cross-sectional view showing the arrangement of heat exchange tubes provided in a conventional device; Figure 6 is an example of the average reaction gas temperature adsorption distribution and methanol concentration in the catalyst layer in a conventional reactor for synthesis of tutanol from synthesis gas. :, conventional reaction 2 in methanol synthesis
An example of the overall heat transfer coefficient value is shown as a function of the gas superficial velocity when the reaction heat generated in the 9-diaphragm medium layer is transferred to the boiling water in the heat exchange tube. FIG. 5 and FIG. 6 are diagrams showing an example of a specific embodiment of the reactor according to the present invention, and FIG. 7 and FIG. 8 are diagrams showing another embodiment of the present invention. In Figures 5 to 8, 1 pressure-resistant outer shell, 2 heat exchange tubes, 3 perforated plate catalyst receiver, 4 mesh, 5 reaction gas supply space, 6 reaction gas gathering space, 7 refrigerant downcomer pipe, 8 refrigerant conduit, 9 refrigerant distribution header,
10 refrigerant collection header, 11 refrigerated gas-liquid drum, 12 refrigerant supply port, 13 refrigerant discharge port, 14 reaction gas supply port, 15 reaction gas discharge port, 16 catalyst filling port, 17 polishing medium outlet, 18 manhole, 19 catalyst layer, 20 particle layer, 21 partition wall, 22 catalyst receiving bottom plate agent 1) Clear agent Ryo Hagiwara - Ichiko ()＼口） Catalyst layer (outlet) ) Oni 5 diagram House 6 diagram Fan 7 diagram 3 Fan 6 diagram

Claims (2)

[Claims] (1) In a reactor in which the reaction gas is caused to flow approximately in the radial direction or approximately in the chordal direction of the reactor while cooling or heating the catalyst layer using vertically installed heat exchange tubes,
A catalyst-filled reactor characterized in that a catalyst layer and a layer of heat exchange tubes r+1j are alternately arranged adjacent to each other. (2) In a reactor in which the reaction residue is caused to flow in the radial direction or approximately in the chordal direction of the reactor while cooling or heating the catalyst layer using a heat exchange tube installed in the vertical direction,
A catalyst layer and a layer of heat exchange tube groups are arranged adjacently and alternately, a structure including the heat exchanger 19 groups is fixed to the upper part of the outer shell, and the heat exchange tube group and the catalyst layer are arranged adjacent to each other alternately. 1. A catalyst layer i14 reactor, characterized in that a catalyst receiver suspended above and housed in the outer shell is housed in a basket.